Glucosamine is the most commonly used chondroprotective supplement for the treatment of osteoarthritis. Chondroitin is the second most commonly used supplement for the treatment of osteoarthritis. Glucosamine is an aminosugar that is incorporated into joint cartilage. It is supplied as a supplement in one of three forms: glucosamine sulfate, glucosamine hydrochloride, or N-acetylglucosamine. Studies show that while all three forms of glucosamine are effective, glucosamine hydrochloride and glucosamine sulfate were more effective than N-acetylglucosamine. Glucosamine is rapidly taken up by cartilage cells and help stimulate the synthesis of joint fluid and cartilage and also helps inhibit the destructive enzymes that can destroy cartilage and proteoglycans. The anti-inflammatory aspect of glucosamine may result from the scavenging of harmful free radicals similar to antioxidants. Glucosamine is used by the cartilage for the synthesis of glycosaminoglycans.
A number of studies in people and pets show that glucosamine is equally effective for treating osteoarthritis when compared to NSAIDs, and without the side effects.
While a number of glucosamine products are available from reputable manufacturers, many of the early major studies done in pets have used a proprietary product (Cosequin and Cosequin-DS) containing glucosamine and chondroitin. Clinical evidence indicates other products from well-known manufacturers are also effective.
Glucosamine is very safe with no side effects. Mild GI upset is rarely observed.
Dosages vary depending upon the product. As a guideline for combination products, a starting dose of 1,000 to 1,500 mg of glucosamine with 800 to 1,200 mg of chondroitin is recommended per day for a 50- to 100-pound dog. This dose is then lowered after 4 to 8 weeks.
Chondroitin sulfate is the major glycosaminoglycan found in cartilage. It also helps slow down enzymes that are destructive to the joint. A study in the 1998 journal Osteoarthritis and Cartilage (as referenced in The Natural Pharmacy: Arthritis, Hoobs and Bucco, Prima, 1999) reported that chondroitin sulfate is an effective treatment for osteoarthritis. Because chondroitin production decreases with age, supplements with this compound may be especially helpful for older pets with arthritis.
Chondroitin is often added to supplements containing glucosamine. While significant studies are lacking, many people feel that adding chondroitin to glucosamine enhances the ability of both substances to repair cartilage.
The trace element manganese is necessary for the synthesis of proteoglycans and serves as an antioxidant. The biochemical reactions that make glycosaminoglycans from glucosamine will not occur efficiently unless manganese is present in the body. An estimated 37 percent of American people may be marginally deficient in manganese, which limits the rate of glycosaminoglycan (GAG) synthesis. One particular glucosamine-chondroitin supplement includes manganese to help ensure that GAG synthesis occurs at the maximum possible rate. Whether or not animals have manganese deficiency is not known so whether manganese supplementation is necessary for animals is unknown as well. Still, including manganese with this supplement will ensure the proper amount of manganese is present for the maximum rate of glycosaminoglycan synthesis, if it is needed.
Glucosamine supplements are available in oral form or as an injection.
Using Chondroprotective Supplements
The following points are important to maximize success when using these chondroprotective supplements:
Safe and effective. They are extremely safe and equally effective when compared to NSAIDS.
Less costly than NSAIDs. Cost may be an issue for some pet owners. The typical daily cost of using a glucosamine-chondroitin supplement is approximately $1.50 per day for a 50-pound dog. This cost can decrease as the dosage of the supplement is lowered to allow the owner to use the lease amount of supplement to maintain pain relief. The comparable cost of the most popular NSAIDs is approximately $2 to $3 per day for a 50-pound dog, making these supplements less expensive, though they are equally effective and lack the potential serious side effects.
Most effective when used early. Since these supplements work by acting on living cartilage cells, they are most effective when used early in the course of the disease. This requires adequate and early diagnosis.
Response may take several weeks. That's because chondroprotective supplements are not drugs but rather nutritional supplements. During the first 4 to 8 weeks, an increased "induction" dose is used and then the dose is lowered as improvement is seen. Additional short-term therapy with conventional and complementary treatments can be used during the induction phase.
Can be effective prior to signs of disease. Supplements can also be effective when no clinical signs are present but disease exists. In my practice, many dogs are diagnosed with hip dysplasia via screening radiographs and started on the supplements pending the need for surgical correction or until clinical signs occur.
Purity of the products is important. Many generic products that sell for much less than patented products do not have the same quality. Studies that have shown the effectiveness of these compounds have used pure grades of products. Products of lesser purity, while they often cost less, may also be less effective. Unlike traditional drugs these compounds are not regulated, and labeling can be inaccurate or misleading. Manufacturers are not required to analyze their products regarding purity, uniformity, or content. Purchase only quality products from reputable manufacturers, as recommended by your doctor.
Reevaluate diagnosis if improvement isn't apparent. Because chondroprotective supplements are so effective in improving symptoms in arthritic pets after 4 to 8 weeks, the diagnosis should be reevaluated after this period of time if improvement is not seen.
Excerpt from The Arthritis Solution for Dogs: Glucosamine used by permission of Prima Publications.
Copyright © 2001 by Shawn Messonnier, D.V.M. All rights reserved. Excerpt from The Natural Health Bible for Dogs & Cats, Prima Publishing, Roseville, CA.